This invention relates to a drive for an auger conveyor of the type which is used to convey feed (or other granular, or powdered, or fluent material) from a bulk feed tank or (other storage container or vessel) to a number of feeders in a poultry or hog house. Typically, such auger conveyors comprise a conduit, which may be a closed tube or and open trough, or a combination of lengths of closed tubes and open troughs, and a "centerless" auger disposed within the conduit. Generally, a centerless auger comprises an open helical coil which does not have a center shaft. The auger is formed of a single elongate wire or rod (which may be either of round or rectangular cross section) which is formed into an open helical coil arrangement having a multiplicity of spaced flights, with the flights being spaced from one another at substantial equal distances from one another. The spacing of the flights from one another is oftentimes referred to as the pitch of the auger. Such centerless augers are advantageous because without a center shaft, they may readily go around turns and can accommodate changes in elevation.
Such auger conveyors are driven by a motor so as to convey feed in axial direction along the conveyor conduit from the supply of feed to distribute the feed to one or more feeders located along the conduit. As shown in the co-assigned U.S. Pat. No. 5,311,839, and in U.S. Pat. Nos. 3,230,933 and 3,415,228, such centerless feed augers may rotate within their respective conduits by means of an electric motor located at one end of the conduit. In this manner, the auger acts like a screw conveyor to move feed axially within the conduit as the auger is rotated. In other feeding systems, the feed conveyor (i.e., the conduit and the centerless auger therein) is arranged in an endless loop with a plurality of feeders located along the loop for conveying feed from a feed source (e.g., a feed hopper) to the feeders along the loop. In such endless loop feed auger conveyors, one or more lengths of a centerless auger are joined together in end-to-end fashion and the endless centerless auger is axially propelled through the conduit so that the flights of the auger axially drag or push feed axially through the conduit. In U.S. Pat. Nos. 2,232,606 and 3,003,464, the auger is shown to be entrained around a drive wheel which in turn is rotated by a motor so as to move the auger axially through a tube to convey a granular material through the tube. As shown in U.S. Pat. No. 4,640,230, an endless, centerless auger may be axially propelled through a conveyor conduit by a gear in mesh with the flights of the auger. The gear was driven by an appropriate gear motor (i.e., an electric motor with a built in gear speed reducer) such that one tooth of the gear engages a respective flight of the auger as the gear is rotated in a radial plane containing the longitudinal axis of the auger. In this manner, the auger is propelled in axial direction through the conduit. While such gear drives work well for their intended purposes, they have certain shortcomings.
In addition, U.S. Pat. Nos. 3,198,320 and 3,249,210 describe center driven drives for rotary augers having a center shaft may be of interest. However, these patents have no disclosure or suggestion of how such a drive could propel an auger axially within a feed conveyor tube.
When such centerless augers are installed in a closed loop conveyor conduit, it is necessary to join the ends of the auger segments for form an endless auger. This may be done by welding or (more commonly) brazing the overlapping ends of the auger together. It is also known that the ends of the auger segments may be joined together by means of mechanical couplers. Reference may be made to U.S. Pat. No. 5,002,421 for a description on one such prior art mechanical auger section connector. However, such prior art auger connectors had certain drawbacks, particularly for use with axial drives for such endless loop augers.